Automatic apparatus for tensioning the warp in looms



I. DUMAIL. AUTOMATIC APPARATUS FOR TEN-SIONING THE WARP IN LOOMS.

APPLICATION FILED MAY 22, i919.

1,355,319, Patented Oct. 12,1920.

fiweruzor: 8 5

z v ibis/{10m i A 2 UNITED STATES PATENT OFFICE.

ISIDORE DUMAIL, OF ROUEN, FRANCE.

A IC AP A AT OR S QNING HE WAR? IN O M T 0 all whom it may concern:

Be it known that I, IsIDoRn DUMAIL, citizen of the French Republic,residing at Rouen, in the Department of Seine Infrieure, France, haveinvented an Improved Automatic Apparatus for Tensioning the arp inLooms, of which the following is a specification.

This invention has for its object to provide an improved a paratus fortensioning the warp in looms, the essentially characteristic feature ofwhich consists in this, that the ordinary tension weights acting uponthe warp-tensioning levers of the loom are replaced by springs whosestrength is carefully adjusted and which exert upon the warp-tensioninglevers an effort which is at its maximum when the warp beam is full, andwhich diminishes gradually as the warp nea-m is emptied, and produces atension equal to m'Z when the warp is used up.

The diminution of the tension of the springs is controlled by a warpbeam feeler, the end of which is always in contact with the warp threadswound on the beam.

The accompanying diagrammatic drawings illustrate by way of example aconstructional form of this invention.

Figure 1 is a front elevation of the improved apparatus.

Fig. 2 is a side elevation of the improved apparatus in its two extremepositions.

a As in the known tensioning apparatus, the improved apparatus accordingto the present invention comprises a warp-tensioning lever 1 (Fig. 1)that exerts a tension upon a-chain 13 which is wound on the pulley 12 ofthe warp beam 11 and thereby produces a powerful braking action upon thesaid pulley, which is usually made of cast iron.

In order to exert this braking action in the place of the ordinary knownweights, the warp-tensioning lever 1 is pulled down by the action of aspring 2 which is placed in tension when the warp beam is filled, by thedownward rocking movement of the lever 8 (Fig. 2) one end of which isfixed to the spring 2. while its other end is attached to a shaft 15fixed to the frame of the loom.

This lever 8 is held in its lower position by the action of the warpbeam feeler which operates in the following manner:

Upon a shaft 5 fixed to the frame of the loom there are fixed two arms,one (4) of which ends in a roller 3 (Figs. 1 and 2) lying Specificationof Letters Patent.

Patented Oct. 12, 1920.

Application filed May 22, 1919. Serial No. 298,994.

upon the warp threads from one end to the other of the warp beam. Theother arm 6 exerts through its roller 7 a pressure upon the lever 8which latter is caused by this pressure to rock on its axle 15, and thusby its end 10 to exert a pull upon the spring 2. The braking action isthen applied to the down by the warp-tension lever 1.

As the warp beam empties, the roller (Figs. 1 and 2) comes nearer to thecenter of the warp beam, and as will be readily perceived on referenceto the figure, the lever 8 will rise and thus diminish the force of thespring 2 which will then exert a less great effort upon the warp-tensionlever 1.

his eifort will be m'l when, the whole of the warp having been unwound,the roller 3 has come in contact with the barrel of the warp beam.

It is to be understood that the more the warp is unwound from the warpbeam, the greater will be the acceleration of the beam. As a matter offact the perforated sheet metal roller in front of the loom, driven bythe pawl of the regulator, will always draw in a unit of time the samelength of thread. But as the turns situated near the center have a lesscircumferential length than the outer turns of the full warp beam, itwill be necessary, in order that these inner turns shall deliver duringthe same period of time the same length of thread as the outer turns,that the warp beam shall rotate faster.

In order to enable the warp beam to rotate with a constantly increasingspeed, it will be necessary that the braking action upon the pulley 12which prevents its motion shall diminish exactly in the same proportion.This result is obtained by the arrangement of the warp beam feeler.Owing to the increased speed of the warp beam, the more warp it deliversand the quicker it delivers the warp, the faster the roller 3 of the arm4, will come nearer to the center of the warp beam 11. Consequently theroller of the arm 6 will rise with an increase pulley 12 by the pull ofthe chain 13 drawn plified. For this reason it is less costly and can bemounted quickly upon any kind of loom.

The improved apparatus is suitable for all kinds of weaving, heavy orlight cloths, provided the tension springs are calculated and correctlyadjusted.

lVhen the over-seer places a warp upon the loom provided with theimproved apparatus,'he takes care to assure that there is a correctpressure upon the threads. If this pressure is too great or too little,he can adjust this pressure by means of the screws 9 and 10 (Figs. 1 and2).

He also adjusts the horizontal'position of the warp-tension lever 1(Fig. 1) by means of the nut 14 which is provided on the end of thebrake chain 13. The weaver then need not attend to the tension of thethreads until the warp has been used up.

The improved automatic apparatus for tensioning the warp is verysuitable for all looms because it assures a greater regularity of theweaving. It is, however, absolutely indispensable for automatic loomswhere the weaver who attends ten, fifteen or twenty looms has notsulficient time to shift the usual tension weights placed on thewarptensioned levers.

Detailed devices (not hereinafter described) may be employed forpreventing if necessary the roller 7 from coming into contact with thelever 8 for the purpose of removing temporarily the pressure in caseswhere the weaver should require to unwind the warp in order to repairsome of its threads. V

It is to be understood that the improved apparatus as. hereinbeforedescribed is given solely by way of example as a constructional form ofthis invention, the essentials of the invention consisting essentiallyin the replacing of the ordinary tension weights in apparatus fortensioning warp in looms, by any device comprising one or more springsof adjustable tension exerting upon the warp-tension levers of the warpbeams, an elfort which isat its maximum when the warp beam is full andwhich diminishes according as the warp beam empties and produces atension equal to m'l when the warp is used up the diminution of thetension .said brake pulley, a warp-tensioning lever acting upon saidbrake chain, an adjustable spring acting upon said warp-tensioninglever, a rocking lever connected to the spring, a rocking shaft, twoarms fixed on said rocking shaft, a roller carried by one of said arms,bearing against the warp threads from one end to the other of the warpbeam, anda roller carried by theother of said arms, exerting a pressureupon the rocking lever, so as to cause the latter to rock and thusproduce a tension of said adjustable spring varying according to thefilling of the warp beam, whereby the braking action of said brakepulley on the warp 'beam is modified through the medium of saidwarp-tensioning lever and said brake chain.

2. In a loom, a warp beam, means including a brake lever for retardingthe movement of the heam, a rocking lever, a spring adjustably connectedbetween said levers, a bell crank having arms of unequal length, aroller carried by the short arm and engaging the rocking lever at a lessdistance from its pivot than the point of attachment thereto of thespring, whereby as the filling of the warp beam becomes smaller, thetension of the spring will be lessened.

In testimony whereof I afiix my signature.

7 ISIDORE" DUMAIL.

Witnesses:

Genus DANZER,

, LUornN CnEsrrN.

